51681650 has 24 divisors (see below), whose sum is σ = 99231744. Its totient is φ = 20005200.

The previous prime is 51681613. The next prime is 51681661. The reversal of 51681650 is 5618615.

It is a happy number.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15122 + ... + 18221.

It is an arithmetic number, because the mean of its divisors is an integer number (4134656).

Almost surely, 2^51681650 is an apocalyptic number.

51681650 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51681650 is a deficient number, since it is larger than the sum of its proper divisors (47550094).

51681650 is a wasteful number, since it uses less digits than its factorization.

51681650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33386 (or 33381 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 51681650 is about 7188.9950618984. The cubic root of 51681650 is about 372.4878605116.

The spelling of 51681650 in words is "fifty-one million, six hundred eighty-one thousand, six hundred fifty".